You must have the number of Shenzhen Mobile to join the cornet cluster network of Shenzhen University. After adding it, it depends on what set meal you have. If it is the provincial network of 15 yuan, it can be used normally in Guangdong Province, such as Huizhou and Guangzhou (short number calling is free). If you run the same city network with 5 yuan, then making and receiving calls in Shenzhen are free. If Shenzhen is in the province, it is free to answer the short number call.